When can I download the Collaboratory?
We have done a great deal of development work on the Collaboratory and are already running some of the detection algorithms on the BOINC platform. We are close to releasing a limited alpha test but for the general release beta test we will need significant additional funding to provide the infrastructure needed to be able to handle the large response we expect. The fundraising timeline is, of course, a lot less predictable than the timelines for programming, observations or posting of educational content, so please stay tuned to our website for announcements. You can help us launch by making a donation! All donations are tax deductible, of course, and greatly appreciated.

How does
PlanetQuest find planets?When the orbit of a planet is aligned with our line-of-sight toward the
star, we can detect the "transit" of the planet as it crosses the
star’s disc. Thus we are actually detecting the shadow the planet casts
onto Earth, which causes a slight drop in the brightness of the star. We then
need to make sure it is a planet and not any of the other things (Earth’s
atmosphere, starspots, noise from the electronic cameras, etc.) that can cause
drops in brightness also, and this statistical check we call the "transit
detection algorithm" or TDA for short. We will soon be adding three more detection algorithms—a double-star transit planet detection algorithm, an eclipsing binary timing planet detection algorithm, and a gravitational lens planet detection algorithm. In addition, we are developing a new SETI detection algorithm based on information theory that will complement existing SETI searches like SETI@home.

How many stars have planets
around them?A little less than 1% of the stable sunlike stars in the solar neighborhood
have giant inner planets orbiting them. This statistic is the result primarily
of the survey done by the radial velocity method of detecting extrasolar planets.
The statistics of outer giant planets (like Jupiter) around other stars have
yet to be constrained, and no-one has found a terrestrial-sized planet around
another sunlike (dwarf) star yet (although large-terrestrial-mass planets have
been found around pulsars, which are exploded giant stars). So about 1% of stars have giant inner planets, and about 7% of these will be orbiting edge-on
(in the line-of-sight between the star and Earth) so that we can detect a transit.
The smaller the star, the larger the transit, so if smaller planets exist, we
should be able to detect them as well around the smallest stars. And it looks
like there could be many more smaller than larger planets around other stars. For an update of the number of extrasolar planets discovered to date, see the Extrasolar Planets Encyclopedia at http://exoplanet.eu/.

What makes a habitable planet?A planet is considered habitable (note that this does not mean inhabited,
but that it has the potential of being inhabited) when liquid water can persist
for long periods of time on the surface, organic material is readily available,
and there is a dependable source of energy. Dwarf stars have good circumstellar
habitable zones (CHZs) or places where water can exist for a long time because
they are pretty stable stars. Giant and supergiant stars change brightness too
quickly to have good CHZs. A planet also has to have an orbit the right distance
from the star (together with atmospheric blanket warming—known as the
"greenhouse effect") to be large enough to recycle its atmosphere
(otherwise the gases in the atmosphere wind up as chemicals in the rocks), and
small enough not to have amassed a huge atmosphere (like Jupiter, Saturn, Uranus,
or Neptune in our solar system). There are many other factors but these three—a
good star, a planet of the right size and distance from the star, and an atmosphere
of the right composition—are the major considerations.

Can
I discover a planet?

Yes. This is the main point of PlanetQuest, to bring the thrill of actual discovery to as many people as possible. This is quite different from your helping us to do science—we want you to be the scientist-astronomer!

Can
I name a planet if I discover it?

The International Astronomical Union assigns official names to stars and planets; however, your name will be entered into the PlanetQuest Discoveries Catalog available on the Web as a classifier of the star and/or codiscoverer of a new planet.

Can
PlanetQuest detect other "Earths"?

This depends on what one means by "other Earths."
An Earth-sized planet around a Sunlike star is (at present) only detectable
from space, and the transit method is the way that the upcoming NASA Kepler
spacecraft mission will detect such planets. However, the PlanetQuest telescopes
(2.0-meters) will be large enough to detect the light from many faint stars.
(These faint stars are small—about 1/100th the brightness of our Sun—and
are called "red-dwarfs" or "M-dwarfs.") These faint stars
are smaller than the Sun—some less than 1/20th the size-area of the solar
disc. If a moth flies in front of a searchlight, the relative dimming is quite
small. But if it flies in front of a flashlight, the relative dimming is much
larger. So, when a planet of a given size (moth) transits (flies in front of)
a solar-sized star (searchlight), it takes much more precision to see a change
than if it transits (flies in front of) an M-dwarf star (flashlight). So, we
will be able to detect the larger of the terrestrial-sized planets around the
smallest stars we can see. If these planets are discovered within the circumstellar
habitable zone (which is much closer than the Earth-Sun distance), then we—actually
you, the discoverer—will have an exciting prospect indeed: a potentially
habitable planet!

Where do the star pictures
come from?We use a large electronic camera (a CCD—similar to the ones in digital
cameras except with more precise ability to record light) at the focus of our
telescopes to record incoming light that has traveled from between 4 and 30,000
light years so that we can record a change in the brightness due to any planetary
transits. We must correct each star image for Earth’s atmospheric effects,
and electronic effects caused by our equipment, and convert the time the image
was taken to the time in the center of the Sun (this is called the heliocentric
julian time or HJD) so that we can compare the times of transits taken at different
points in Earth’s orbit around the Sun (without this correction, one could
be almost 17 minutes off).

What is a light curve?The light curve of a star is a plot of its brightness against the time
it has that brightness. Most of the time this is given in "differential
magnitudes" or the brightness variation of a given star compared with other
stable (or "standard") stars in the same star field and so imaged
(electronically photographed) at the same time. The light curve is corrected
for star color differences, precise time, and all instrumental effects so that
any remaining brightness variations are intrinsic to the star itself—or
to a planet orbiting that star.

What is SETI?Radio SETI (Search for Extraterrestrial Intelligence) is the effort to
detect narrow-band radio signals. Nothing known other than technology (i.e.,
a radio station) can make narrow-band signals—that is, signals that you
can tune into and out of with just a turn or two of the radio dial. (Incidentally, optical
SETI uses the same reasoning, but here again apparently only technology can
produce light pulses that last a billionth [nano] of a second—although stars
can collapse to make a millisecond pulsar that can pulse a thousand times per
second.) PlanetQuest plans to collaborate with the SETI Institute's Allen Telescope Array (see http://www.seti.org/seti/projects/ata/) as well as other radio observatories to apply a new method, developed by some of the PlanetQuest collaborators, of ascertaining if radio signals are actual communications using information theory. Current projects could detect whether there is an extraterrestrial radio transmitter, while the new approach—part of the PlanetQuest Collaboratory—will detect whether the content of any radio flux is consistent with the information content of an intelligent communication. We have based this work on the study of the communication systems of several intelligent species such as squirrel monkeys, bottlenose dolphins, and humpback whales. More information about this can be ascertained by writing us at info@planetquest.org.

What is a variable star?
About 15–20% of the stars in the sky vary significantly in brightness, and
there are about 200 classes of these types of stars. Some can be used to measure
distances across the Galaxy, some to directly measure the size of stars, some
to study the stability of stars, some to study the birth of stars, and there are
many other uses. Any discovery of a particular type of star by a PlanetQuester
will be a great help to the astronomical community. What if your star is stable?
Then it is also of interest, as stable (that is, nonsignificantly variable) stars
will have potentially stable circumstellar habitable zones (CHZs), which is also
great!

What is the transit detection algorithm?The transit detection algorithm (or TDA) is a statistical test of the presence
of a planet in the light curve of a star (the light curve is a plot of the brightness
of the star with time). It uses models of variable star types and compares them
with the light curve of the unclassified star to see which one matches the best.
It then proceeds to compare models of possible planet transits (varying the
planet size, orbital period, and orbital phase—where it started in its
orbit compared with when we started to observe it, sometimes called the orbital
"epoch") to see which one of these matches the best, if any. Thus,
when we have a candidate planet we can say with what dependability we know it
is a planet (called the "confidence" level). The complementary way
of looking at this is that we will also know what is called the "false
alarm" rate—that is, at what level we are being fooled into thinking
it is a planet when it is not. This number should be as small as possible and
the confidence limit should be as high as possible. This is what takes so much
computational time.

What is the PlanetQuest
star catalog?The PlanetQuest star catalog is where you go down in history as a true
astronomical discoverer. Astronomers, astrophysicists, astrobiologists, and
historians of science will know that you were the first to explore and classify
a particular star. Also, that some of you will be discoverers of whole new worlds
yourself. The Star Catalog will record all discoveries so that not just the
professional astronomical community will know who made these discoveries but
also you will find out how your friends are doing with their discoveries. Many
many of the discoveries will be most important to the scientific community for
centuries to come.

Where
are PlanetQuest headquarters?PlanetQuest headquarters are in Sausalito, California in the San Francisco Bay Area. Our telescope network at present includes the oldest professional reflecting telescope in the world (the Crossley 0.9-meter at Lick Observatory), a 1-meter at Siding Spring Australia (summer 2005), the PASS array in the Canary Islands, and the Vulcan South telescope at the South Pole. We have also been invited to join an observing consortium at the Calar Alto Observatory in southern Spain and to have two PlanetQuest telescopes at Cerro Tololo Inter-American Observatory in Chile.

Who
are the people of PlanetQuest?See the "People" section.
The main people are astronomers whose expertise is extrasolar planet detection,
engineers whose expertise is signal detection statistics, computer scientists
whose expertise is distributed computing, educators whose expertise is fun in
science learning, and business people whose expertise is creative support of
a worldwide observatory and educational system. Right now we have about a dozen volunteers donating various percentages of their time. We are all looking forward to gearing up to full time work on PlanetQuest as soon as funding for this can be established.

How can I send
questions in to PlanetQuest?Just send your questions to info@planetquest.org
and we will answer them in our Frequently Asked Questions section. They will
be listed here and searchable by keyword.

How can I stay
infomed about progress at PlanetQuest?Sign up for our Friends
of PlanetQuest newsletter! We send the latest news and up-to-date information
to our supporters in this way, as well as on our News page right on this website.

Will PlanetQuest
run out of stars?PlanetQuest will only run out of stars if we run out of enthusiasm
for looking at the heavens—not likely! We plan to add as many telescopes
as needed to keep PlanetQuest going for everyone on Earth who would like to
participate in this exploration of the heavens. And there are enough stars to
vastly outdistance even the growing population of Earth; we will just need the
telescopes to reach enough of them to continue the adventure. Email us at donate@planetquest.org
for more information and see our Missions
in Need page under Donate.